Tape automated bonding feeder and lead forming apparatus

ABSTRACT

An tape automated bonding feeder apparatus employs a vertical carrier extraction unit to successively supply electronic circuit components to an output station from which a component is seized for placement and attachment to a circuit board. The feeder apparatus, which may be mounted on a rollable cart, includes a generally rectilinear housing on a top plate of which one or more magazines are mounted. A magazine contains a stack of circuit component carriers. The bottom of the magazine has a carrier extraction unit which controllably allows an individual component carrier at the bottom of the stack to drop away onto an underlying carrier shuttle. The carrier shuttle is supported for movement betweeen the magazine and a lead forming unit. The lead forming unit detaches a component from the carrier and forms the leads of the excised component for mounting the component to a circuit board. A processed component transport unit is coupled to an anvil of the lead forming unit and transports a processed component to the output station.

FIELD OF THE INVENTION

The present invention relates in general to the assembly of electronicprinted circuit boards and is particularly directed to an apparatus forexcising individual circuit components from tape automated bonding (TAB)carriers, forming the leads of the excised components and delivering theprocessed components to a presentation station for pick and placetransport by an associated part seizure system, such as a robotic pickand place system.

BACKGROUND OF THE INVENTION

As continuing refinements in micro-miniaturization techniques haveincreased the component occupancy densities of printed circuit boards,misalignment and imprecise shaping or formation of component leads havebecome significant concerns of system manufacturers, particularly thoseemploying surface mount devices such as narrow pitch leaded chipcarriers. Circuit components having high count, very narrow pitch leadsare often processed using a tape automated bonding scheme, in which thepart (the electronic circuit component) to be mounted on a circuit boardis temporarily retained in a surrounding support frame or carrier. Theextremely thin and narrow pitch leads of the part extend between thepart and the frame and support tape is similarly employed to retain thepart in the carrier during handling.

Because the retention carrier is relatively thin compared to itsedgewise dimensions, it is customary to arrange a plurality of carriersin a stacked configuration. Individual carriers to be processed areseparated off the top of the stack in a sideways direction, similar todealing cards from the bottom of the deck. A separated carrier is thenplaced on a lead forming device, so that the part may be detached orexcised from the carrier and the leads formed and trimmed for placementand attachment to a printed circuit board.

A fundamental problem to horizontal translation of a carrier from thetop of the stack is the fact that the carrier surfaces are not perfectlysmooth, so that the lowermost carrier may hang up on the next carrier,thereby hindering the feed and lead formation process. In addition,because `dealing` a carrier off the bottom of the stack involveshorizontal or sideways movement (in a direction orthogonal to that ofthe stack) the feed mechanism requires a considerable hardware volume.

SUMMARY OF THE INVENTION

In accordance with the present invention, the above problems ofconventional TAB feeder systems are obviated by a new and improvedreduced hardware volume apparatus which successively feeds individualones of a plurality of carrier-retained electronic circuit components toa pick and place device for placement and attachment to a circuit boardwithout having to sideways translate the carriers of the stack, therebypreventing surface anomalies on the surfaces of adjacent carriers in thestack from impeding the feed process. (As used in the presentspecification, a TAB carrier implies a carrier employed in a tapeautomated bonding system or any similar type system, such as a tapepack.)

For this purpose the present invention employs a compact, substantiallyrectilinear housing on a top plate of which at least one carriermagazine is mounted. In a single magazine configuration, only onemagazine is affixed to the top plate of the housing directly above acarrier extraction or delivery opening. In a multiple magazineconfiguration, a plurality of magazines are arranged side by side on ahorizontally translatable support plate, which permits a selectedmagazine to be controllably positioned over the carrier delivery openingin the top plate of the housing.

A magazine stores a plurality of circuit component carriers in avertical, stacked configuration. The bottom of the magazine contains acarrier extraction unit which controllably allows the bottom-mostcarrier to drop away from the stack, while retaining the remainingcarriers within the magazine. The dropped carrier falls onto a carriershuttle, which is supported on a transport rail for movement between themagazine and a lead forming unit that is spaced apart from the magazinein the vicinity of a part presentation station.

The lead forming unit includes a vertically translatable die press and ahorizontally transportable anvil. When the carrier shuttle transportsthe carrier to the lead forming unit and places the carrier on theanvil, the die press is lowered onto the anvil in order to detach thepart from its carrier and form the leads of the excised part into agull-wing shape for surface-mounting the part onto a circuit board. Theanvil is supported on its own transport block which rides on thetransport rail and transports the processed part to the presentationstation.

The carrier shuttle is configured to retain a captured carrier in agenerally horizontal orientation. The carrier extraction unit includes ashutter mechanism which controllably opens to allow the lowermostcomponent carrier within the magazine to drop to the shuttle. It alsoincludes an adjacent carrier-engaging unit which retains the nextlowermost carrier in place as the lowermost carrier in the magazine isallowed to drop away through the open shutter. After the lowermost orbottom carrier has dropped away from the stack, the carrier extractionunit allows the next lowermost carrier to move into position as thelowermost carrier within the magazine.

The carrier extraction unit's shutter mechanism has a variable sizeaperture which, in a first degree of opening, is of a size less thanthat of an individual carrier, so as to effectively prevent a carrierwhich is adjacent to the aperture from passing through it. In a seconddegree of opening, the aperture is of a size sufficient to allow acarrier adjacent to the aperture to pass through the aperture and ontothe carrier shuttle. The carrier extraction unit further includes aplunger device, which is coupled with the shutter mechanism and isarranged to engage the next lowermost carrier when the shutter mechanismis operated to bring the aperture to its second degree of opening.

The variable size aperture of the shutter mechanism is formed by meansof pair of relatively translatable frames. A first of these frames isaffixed to the bottom of the magazine. The fixed frame has a firstwindow sufficient to accommodate the second degree of opening A second,translatable frame slides along the top of the fixed frame and has asecond window sufficient to accommodate the second degree of opening fora first mutually overlapping position of the translatable frame with thefixed frame. A pair of springs normally bias the translatable frame to asecond mutually overlapping position with the fixed frame, so that saidfirst and second windows have a mutual overlap associated with the firstdegree of opening and thereby prevent a carrier from passing through theaperture.

The shutter mechanism further includes a pair of cam members, which arerotatable about respective axes passing through the fixed frame and arecoupled with the translatable frame such that, for the second mutuallyoverlapping position of the translatable frame relative to the fixedframe, the cam members are rotated to positions within the first degreeof opening of the aperture and, for the first mutually overlappingposition of the translatable frame relative to the fixed frame, the cammembers are rotated to positions out of the second degree of opening ofthe shutter The cam members are sized to lie substantially within athickness dimension of the translatable frame, so as to provide carriersupport along one edge while an edge of the translatable frame providescarrier support along another edge of the carrier.

The plunger device is mounted to the translatable frame and includes aplunger element, the nose of which is positioned and sized to engage asidewall of the next lowermost carrier as the translatable frame ismoved from its second mutually overlapping position to its firstmutually overlapping position with the fixed frame. As a result, duringmovement of the translatable frame from its second mutually overlappingposition to its first mutually overlapping position with the fixedframe, the plunger element frictionally abuts against a sidewall of thenext lowermost carrier in the magazine and causes that carrier to besupported at its opposite sidewalls between an interior wall of themagazine and the plunger element.

The carrier shuttle onto which the bottom carrier in the magazine isdropped by the operation of the carrier extraction unit includes agripper mechanism having first and second gripper fingers which serve toretain the dropped carrier in a horizontal orientation. The gripperfingers are controllably translatable toward and away from each other ina horizontal direction, with each finger having a ledge upon which adropped carrier is supported along its edges, and an overhang `roof`plate that partially overlaps the ledge.

The gripper fingers are held by a gripper finger support which retainsthe gripper fingers in spaced-apart relationship such that the gripperfingers are urged together by bias springs toward a minimum separationdistance therebetween. It also includes a controllable finger spreadingelement which controllably increases the separation between the gripperfingers to allow for capture of a carrier dropped from the magazine, onthe one hand, and for discarding a spent carrier, on the other hand. Thegripper finger support comprises a base support portion and first andsecond finger retention elements extending in spaced-apart relationship.Shaft members are supported by the finger retention elements and passthrough the gripper fingers, so that the gripper fingers arehorizontally, translationally supported by the shaft elements.

The gripper finger support further includes a pneumatic rod arrangedparallel to the shaft elements. The axial bore in the rod is ported to acontrolled air supply and opposite ends of the rod are coupled torespective bores in the gripper fingers to controllably apply apneumatic spreading force against the bias springs. The gripper fingersare further configured to engage a mechanical spreading element locatedbeneath the top plate of the feeder at the magazine, such that when theshuttle is brought to the magazine, engagement with this mechanicalspreading element will increase the separation between the gripperfingers against the normal together-urging retention of the gripperfingers by the gripper finger support.

A shuttle base is mounted to a block which rides on the transport rail.A vertical displacement unit comprises an arrangement of translationcolumn members that are supported by the shuttle base and support thegripper mechanism for vertical translational movement relative to theshuttle base.

When the carrier shuttle is translated along the rail to the leadforming station, the gripper finger support is lowered onto the anvilsuch that alignment pins on the anvil engage carrier registration holesin the carrier. The die press unit is then operated to bring a leadforming die into controllable engagement with the anvil, therebyexcising the part from the carrier and forming the leads of the excisedpart. The lead forming die is rigidly affixed to a translatable diesupport member, and the force exerted by the die upon leads of the partis externally controllable, so as to assure precise lead formation. Theanvil includes an ejector element which is controllably urged intocontact with a formed part that has been excised from the carrier, so asto lift the part off the anvil and facilitate vertical access to andcapture by a part seizure device (robot end effector).

The feeder itself may be mounted to a transport cart which includes abase frame supported for rolling movement upon a floor surface. Asupport frame is mounted on the base frame, and includes a heightadjustment mechanism for adjusting the height of the feeder. A mountingplate is affixed to an upper end of the height adjustment mechanism, soas to provide a support base for the feeder. A spent carrier discard binis supported by the support frame beneath the location of the feederwhere support carriers are discarded. A pair of alignment elements areaffixed to the mounting plate, and are arranged to engage associatedalignment members on an adjacent circuit board assembly unit.

In the course of the assembly of a printed circuit board, as by way of ahost-directed robotic pick and place system, a plurality of TAB feedersmay be arranged together, with the host machine supervising theoperations of each component feed unit. Each component feed unitincludes its own local programmable logic controller unit havinginterfaces for sensor, drive and signalling elements of that unit. Tofacilitate communications between the host machine and the respectivefeeders, the present invention employs a distributed multiplexsignalling bus to which the attendant controllers of the plurality ofcomponent feed units are coupled and through which multiple feed unitsare selectively addressed by the host machine in the course of accessingcomponents for placement and attachment to a circuit board.

In accordance with a further embodiment, the feeder may support aplurality of magazines, in each of which a plurality of circuitcomponent carriers are arranged in a stacked configuration, translatablymounted with respect to the extraction aperture in the feeder housing.As in the single magazine embodiment, each magazine has a carrierextraction unit at its base which controllably allows an individualcomponent carrier to drop away from the stack, when that magazine isaligned over the extraction aperture.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1, 2 and 3 show respective isometric, side and top diagrammaticviews of a first embodiment of a tape automated bonding (TAB) feederapparatus of the present invention;

FIGS. 4-11 are diagrammatic side view illustrations of the individualcomponents of the feeding system of FIGS. 1-3 during respective steps ofone cycle of operation;

FIG. 12 diagrammatically illustrates an exploded view of theconfiguration of a carrier magazine and an associated carrier extractionunit;

FIGS. 13-19 are additional side and top views of portions of themagazine and the extraction unit that illustrate how the parts engageone another to allow only a single carrier at the bottom of the stack todrop away onto the shuttle;

FIGS. 20-28 show the component parts and the overall configuration of acarrier gripper;

FIGS. 29 and 30 are respective diagrammatic top and partial side viewsof a translatable anvil;

FIGS. 31 and 32 are respective diagrammatic plan and partial side viewsof a lead clamping, excising and forming unit;

FIG. 33 is a diagrammatic side view of a transport unit for a tapeautomated bonding feeder apparatus of the present invention; and

FIG. 34 shows a multiple magazine embodiment of the feeder apparatus ofthe present invention.

DETAILED DESCRIPTION

FIGS. 1, 2 and 3 show respective isometric, side and top diagrammaticviews of a first embodiment of a tape automated bonding (TAB) feederapparatus of the present invention as comprising a housing 10 upon whicha single, vertically configured, TAB carrier magazine 11 is removablymounted. In the diagrammatic isometric illustration of FIG. 1, themagazine is Magazine 11 stores a plurality of TAB-based circuitcomponent carriers 13, that have been inserted through a topside opening15, so as to form a `coin stack` arrangement 18 of carriers. The stackedcarriers are visible and physically accessible by means of a verticalwindow 17 in an endwall 19 of the magazine. The carrier magazine 11 isremovably mounted to housing 10 by way of a base bracket 20 directlyabove an aperture 22 in a top plate 23. Aperture 22 is sized slightlylarger than an individual carrier, so as to permit a carrier to dropfrom the bottom of the stack 18 within the magazine onto a carriershuttle 26, shown in the side view of FIG. 2. Carrier shuttle 26 ismounted atop a block 27 that rides along a support rail 28 mounted to abottom plate 29 of the housing, so that carrier shuttle 26 may becontrollably translated between the magazine 11 and a die press station31.

As will be described in detail below, a carrier extraction unit 12 atthe base of magazine 11 controllably singulates an individual componentcarrier from the bottom of the stack 18 through the aperture 22 in thetop plate onto the shuttle. By `singulate` is meant the delivery orextraction of a single or individual part from the stack onto theshuttle. The translatable block 27 to which the carrier shuttle ismounted is driven along support rail 28 by the output shaft (push rod)of a control air cylinder 33, thereby translating the carrier shuttleback and forth between magazine station 14 and die press station 31.

At die press station 31, a die press 35 is mounted to an upper top plate37 of the housing, and supports a vertically translatable lead-clamping,excising and forming unit 39, which is arranged to engage a horizontallytranslatable anvil 41, when the anvil is positioned directly beneath thepress. Anvil 41, like shuttle carrier 26, is mounted to a block 43,which is controllably translated by means of an associated control aircylinder 45 along support rail 28 between die press station 31 and apart presentation station 51 at the right end of base plate 29, asviewed in the Figures.

When anvil 41 is located beneath the die press 35 at the die pressstation 31, it is in position to receive a carrier that has beendelivered to it by the translation of the carrier shuttle from themagazine station to the die press station. The die press is thentranslated vertically downward onto the anvil, so as to excise the partfrom the carrier and form the leads of the severed part. The shuttlethen lifts the spent carrier off the anvil and is translated back to themagazine station. Simultaneously, the anvil 41 and the formed part aretranslated to the presentation station 51, so that the formed part maybe seized vertically by a pick-up device, such as a robot end-effector,and mounted to a printed circuit board.

Before describing the structural details of the individual components ofthe feeding system of FIG. 1, the overall arrangement and operation ofthe system will be described with reference to the side viewillustrations of FIGS. 4-11, which show respective locations of thecomponents of the system (including a programmable logic controller unit100 through which the operations of the system are controlled under thedirection of a host controller) for the sequential steps of one completecycle of the system. Programmable logic controller unit 100 ispreferably contained within a housing mounted adjacent to housing 10,which also includes electrical and pneumatic interfaces (e.g. solenoidvalves) for the respective sensor, drive and signalling elements of thesystem as will be described below. Control communications between eachTAB feeder and its associated host controller are preferably carried outby way of a distributed multiplex signalling bus to which one or morefeeders are coupled so as to permit multiple feeders to be selectivelyaddressed by means of a single cable set from the host machine. Eachfeeder unit preferably has a presettable thumbwheel switch through whichits address may be prescribed, to facilitate varying on-lineparticipation of each feeder in a circuit board manufacturing system.Rather than detail the control program through which the host directsthe operation of a TAB feeder cycle, the following discussion will setforth the sequence of operations of a carrier cycle. For details of thecontrol program itself, attention may be directed to the accompanyingAppendix.

FIG. 4 diagrammatically illustrates the starting location (magazinestation 14) of carrier shuttle 26 directly beneath magazine 11. Theshuttle itself includes a set of carrier gripper fingers 61 mounted to agripper support 63, which is supported and guided on a set of posts 65for vertical movement with respect to a shuttle base 67. Also mounted toshuttle base 67 is a spent carrier discard device 71 comprised of aspent carrier discard control cylinder 73 and a push plate 75 mounted tothe output shaft of cylinder 73. As will be described below, during theshuttle carrier's return to the magazine station 14 from the die pressstation 31, discard control air cylinder 73 is operated to cause pushplate 75 to engage a previously spent carrier (namely one from which acircuit part has been excised at the die press station) that has beendiscarded onto a set of spent carrier rails 77. Rails 77 are supportedin cantilever fashion above the shuttle carrier rail 28 and extend to alocation directly beneath the magazine. The horizontal spacing betweenrails 77 and the separation between the vertical posts 65 of the shuttle26 are dimensioned so that the spent carrier rails fit between thevertical posts 65 of the shuttle. Consequently, as the shuttle istranslated between magazine station 14 and die press station 31, theshuttle posts 65 pass outside the rails without hinderance.

With shuttle 26 initially positioned at its starting location atmagazine station 14, its controller 100 looks for its addresstransmitted from the host controller, indicating that it is to begin acarrier cycle. When the controller sees its address on thecommunications bus it transmits an acknowledgement (ACK) signal to thehost processor, indicating that it is ready to proceed. In response tothe acknowledgement signal, the host transmits a START flag, instructingthe feeder to execute a carrier cycle. Unless an error is encountered inthe carrier extraction and processing sequence to be described below,controller 100 proceeds without further dialogue with the host. If anerror is encountered, an ERROR flag is raised by the controller,informing the host of a problem with the feeder, so that a systemoperator may be advised and corrective action taken. An error flag isgenerated upon the occurrence of any of the following conditions: 1) ifa part has failed to drop onto the shuttle, so that the carrier sensordoes not see the carrier in place; 2) if a part has been successfullycaptured by the shuttle, but not properly delivered to and placed inregistration on the anvil; and 3) an attempt is made to start a new feedcycle without seeing an eject flag.

At the beginning of the cycle, carrier extraction unit 12, which isinitially positioned at the base of magazine 11, controllably extractsan individual component carrier 13 from the bottom of the stack 18 bypermitting the bottom-most carrier to drop away from the stack throughaperture 22 in top plate 23 and onto the carrier gripper 61 of theshuttle. As will be described in detail below with reference to FIG.20-28, carrier gripper 61 has a pair of horizontally adjustable gripperfingers that are configured and adapted to engage a spreading wedgemember (not shown in FIG. 4), which is mounted to the bottom of topplate 23 when the shuttle is positioned at magazine station 14. In thisposition, the spreading wedge member engages the gripper fingers andurges the fingers apart sufficiently to permit a dropped carrier to cometo rest upon respective horizontal ledges of the fingers, but not so farapart to permit the carrier to drop past the gripper fingers to thespent carrier rails 77. When the shuttle departs the magazine station,the gripper fingers disengage the spreading wedge member, so that a pairof springs (not shown in FIG. 4) may bias the gripper fingers togetherand allow a pair of overhang plates (also not shown in FIG. 4) toslightly overhang the peripheral edges of opposite sides of the capturedcarrier, whereby the gripper retains the carrier in a horizontalorientation during placement on the lower die anvil.

With an individual carrier 13 that has been extracted from the bottom ofthe stack now captured by carrier gripper 61, the carrier shuttle istranslated by its drive air cylinder 45 along rail 28 to die pressstation 31, as shown in FIG. 5. When the shuttle reaches the die pressstation 31 (FIG. 6), the carrier gripper 61 is lowered onto anvil 41(located directly beneath die press 35) such that a pair of verticalalignment posts on the anvil engage sprocket holes (or other similartooling apertures) in the carrier and thereby properly align the part tobe excised from the carrier with the anvil 41, as shown in FIG. 7.

With the part now positioned on the anvil 41 directly beneath the diepress 35, the die press is translated vertically downward (FIG. 8) tosever the part from the carrier and form the leads of the severed part.At this time corner tie strips are also severed so as to completelyexcise the part from the carrier.

Next, as shown in FIG. 9, the lead forming die is retracted and thespent carrier is lifted off the anvil The shuttle carrier and the spentcarrier are then translated back to the magazine station, as the anvil41, which now carries the formed part, is simultaneously translated tothe presentation station 51, where the part may be seized vertically bya pick-up device, such as a robot end-effector, as shown in FIG. 10.

With the anvil and the formed part translated to presentation station51, an `in position` signal is generated by controller 100, informingthe host that the part is in position to be picked up. When a pick-updevice is brought to the presentation station, the host transmits anEJECT signal to the controller which responds by activating an ejectordevice within the anvil beneath the formed part, so that the part may bereadily seized by the pick-up device Should the host device attempt toinitiate a new cycle without having transmitted an EJECT signal, thecontroller will generate an error flag, indicating that it still has apart to be picked up. With the part picked up, the anvil remains atoutput station 51 until another cycle begins, whereupon it is returnedto the press station 31.

During the shuttle carrier's return to the magazine station 14, discardcontrol air cylinder 73 is operated to raise push plate 75, so that itmay engage and push a previously spent carrier (currently resting onrails 77) off the end of the rails and into an underlying spent carrierbin 49, as shown in FIG. 11, thus completing one carrier processingcycle. When the shuttle carrier returns to the magazine station, carriergripper 61 is fully opened by means of a pneumatic actuator (to bedescribed), causing the presently captured carrier from which a part hasbeen excised to drop onto the discard rails 77, thus completing thecycle.

Once the spent carrier has been dropped from the shuttle onto the spentcarrier rails 77, a new cycle begins, as the pneumatic force which fullyopened the gripping fingers of the shuttle is released, allowing thegripper fingers to engage the aforementioned spreading wedge member, soas to impart a slight opening of the gripper fingers sufficient to allowa new carrier dropped from the magazine to be captured.

As will be described in detail below, a significant feature of thepresent invention is the manner in which carriers are delivered from themagazine by a mechanism which permits the carriers to drop off thebottom of the stack, one at the time, while retaining the remainder ofthe carriers within the stack. This vertical dropping of the bottom-mostcarrier away from the stack avoids the possibility of adjacent carriershanging up on one another, as may occur if an attempt were made to slidean end carrier off the stack, as is done in conventional stacked carrierfeed systems.

FIG. 12 diagrammatically illustrates an exploded view of theconfiguration of magazine 11 and its associated carrier extraction unit12, while FIGS. 13-19 are additional side and top views of portions ofthe magazine and the extraction unit that illustrate how the partsengage one another to allow only a single carrier at the bottom of thestack to drop away onto the shuttle. The magazine is comprised of a pairof vertically extending, generally mirror image, U-shaped wall units 81,82 that are joined together along rear walls 83, 84, as by way ofmachine screws 86. The bottom of each of rear walls 83, 84 has a removed(and recessed) region 88 to allow for the horizontal translation of aslidable frame 90 over the top surface 91 of a fixed bottom frame 92which has a set of holes 94 for bolting frame 92 to the bottom surfaceof wall units 81, 82. Similarly, an upper interior surface portion ofeach of wall units 81 and 82 may be provided with a recess or slot 81S,82S to accommodate opposite sides of the cover flange of a the shippingbox (not shown) in which carriers are supplied by a carrier vendor.Namely, slots 81S, 82S facilitate the mating of the top, open end of themagazine directly with the shipping box, so that the carriers in theshipping box may be readily stacked in the magazine, as is, from theshipping box. To load the magazine directly from the shipping box, themagazine is inverted and slipped over the flanges at the cover of theshipping box, so that the box and the magazine are mutually verticallyaligned as an integral unit. The magazine is then inverted to allow thestack of carriers in the shipping box to pass into the magazine, and themagazine base is mounted to the feeder housing.

Bottom frame 92 is slightly longer than the depth of the wall units sothat it extends just beyond the bottom edge of each wall unit, as shownat 101, 102 in FIG. 13, thereby allowing the magazine to be rigidlyaffixed to the housing by a pair of chamfered clamps 104, 105,respectively mounted to the top surface 24 of housing top plate 23.Generally centrally located at edge portion 101 of bottom frame 92 is adetent 106 which engages an alignment pin 107 in top plate 23 of thehousing, thereby aligning the magazine above aperture 22. Clamp 104 isfixed, while clamp 105 is manually translatable by means of a griphandle 106 and incorporates an internal spring (not shown) to bias theclamp toward aperture 22. As the magazine is being, clamp 105 is urgedback against its spring bias, so as to allow the bottom frame 92 to beseated flush against the top surface 24 of the top plate. The clamp thenreturns to its biased-closed position, so as to secure edge 102 of frame92 in place.

Bottom frame 92 has an aperture or `drop slot` 111 sized incorrespondence and aligned with the interior 16 of the magazine Adjacentto a rear edge 113 of aperture 111 are a pair of pins 114, 115 uponwhich respective generally S-shaped cam members 116, 117 are rotatablymounted, such that cam members 116, 117 are in the same plane asslidable frame 90 atop bottom frame 92 and have respective outer ends121, 122 that engage detents 124, 125 in frame 90. Cam members 116, 117have interior ends 131, 132 which are adapted to extend over aperture111 of bottom frame 92 when the magazine is in its at rest or storagemode, as shown in FIG. 14. In this mode, all of the carriers that havebeen inserted into the magazine through the top opening 15 are securelyretained in a stacked configuration.

Adjacent to side edges 118, 119 of drop slot 111 of bottom frame 92 areadditional pins 144, 145 to which first ends of horizontally extendingcompression springs 146, 147 are connected. Second ends of these springsare connected to pins 151, 152 which are mounted adjacent to side edges154, 156 of an aperture 99 in slidable frame 90. Pins 144, 145 passthrough elongated slots 161, 162 in slidable frame 90, thereby causingextension springs 146, 147 to normally bias slidable frame toward rearwalls 83, 84 of the magazine until pins 144, 145 in bottom frame 92 abutagainst ends 148, 149 of elongated slots 161, 162 of slidable frame 90,thereby delimiting relative movement between frames 90 and 92.

Aperture 99 of slidable frame 90 is sized as diagrammaticallyillustrated in FIG. 15, which shows the position of slidable frame 90above bottom frame 92 for the storage mode of the magazine. With pins144, 145 abutting against ends 148, 149 of elongated slots 161, 162 offrame 90, a forward edge 150 of slidable frame 90 slightly overlaps theforward edge 120 of bottom frame, by an overlap region 130 (e.g. on theorder of an eighth of an inch). Also, for this relative position offrames 90 and 92, the outer ends 121, 122 of cam members 116, 117 arepositioned by detents 124, 125 of slidable frame 90, such that theinterior ends 131, 132 of cam members 116, 117 overlap the rear edge 113of drop slot 111 in bottom frame 92. As a result, within the plane ofslidable frame 90, overlap region 130 of frame 90 and interior ends 131,132 of cam members 116, 117 effectively constrict the opening defined bythe mutual overlap of aperture 99 of slidable frame 90 and aperture 111of bottom frame 92, and provide support surfaces upon which oppositeedges 171 and 172 of the bottom-most carrier 13B rests, as shown in thepartial side view of the bottom of the magazine in FIG. 16.

In accordance with the present invention, bottom-most carrier 13B isextracted from the stack by translating slidable plate 90 against theaction of bias springs 146, 147 toward the endwall 19 of the magazinewhere window 17 is defined, namely to the right as viewed in FIGS. 15and 16. For this purpose, a block 181 has a cylindrical bore 182 in abore 182 of which a cylindrically shaped button or plunger 183 isretained against a spring seated at the bottom of the bore. Block 181 ismounted to a rear surface region 185 of slidable frame 90. Plunger 183has a generally conically shaped nose portion 191 positioned and sizedto engage the side surface 192 of the next-to-the-bottom carrier 13N,when frame 90 is urged to the right, as shown in FIG. 13. The oppositeside surface 194 of carrier 13N is also urged into abutment with theinterior surface 195 of magazine endwall 19 as slidable frame is sotranslated.

In order to extract the bottom-most carrier 13B from the stack, block181 is displaced toward the interior of the magazine (to the right asviewed in the Figures), for example either mechanically orpneumatically, thereby translating slidable frame 90 against the biasingaction of extension springs 146, 147. During this extraction mode of themagazine, the rightward translation of frame 90 causes cam member 116 tobe rotated clockwise about pin 114 and cam member 117 to be rotatedcounter-clockwise about pin 115, so that the interior ends 131, 132 ofthe cam members no longer overlap aperture 111 of bottom frame, as shownin FIG. 17. As also shown in FIG. 17, the translation of frame 90displaces forward edge 150 of aperture 99, so that forward edge 150 ofslidable frame 90 no longer overlaps forward edge 120 of bottom frame92, thereby allowing bottom-most carrier 13B to drop free throughaperture 22 in plate 23. As block 181 is pushed inwardly, the noseportion 191 of button 182 engages the side surface 192 of thenext-to-the-bottom carrier 13N, as frame 90 is urged to the right, asshown in FIGS. 18 and 19, so that the opposite side surface 194 ofcarrier 13N is urged into abutment with the interior surface 195 ofmagazine endwall 19, thereby effectively jamming carrier 13N within themagazine and preventing it and the remaining carriers above it fromdropping together with bottom-most carrier 13B. The spring bias ofbutton 183 maintains the side force against carrier 13N as block 181 isallowed to return to its static condition position under the bias ofextension springs 146, 147. As slidable frame moves back to its previousposition, cams 116, 117 rotate back into their aperture-constrictingorientations and forward edge 150 of frame 90 again overlaps edge 120 ofaperture 111 of bottom frame 92. As block 183 and frame 90 continuetheir return movement to the static condition, button 183 separates fromthe side edge 192 of carrier 13N allowing carrier 13N and the remainderof the stack above it to drop onto cams 116, 117 and overlap region 130.

FIG. 20 diagrammatically illustrates an exploded view of theconfiguration of the shuttle 26, while FIGS. 21-24 are additional side,top and end views of portions of the shuttle illustrating how the partsof the shuttle engage one another to securely capture, retain anddiscard a carrier that has been delivered from the magazine The carriergripper, shown at 61 in FIG. 20, is comprised of a pair of horizontallyoriented gripper fingers 201, 202 which are spaced apart from oneanother by a sensor block 204, in a forward cavity 206 of which acarrier sensor 208 (see FIG. 21) is retained. The carrier sensorincludes a light emitting diode and an adjacent photodetector elementoriented with respect to where a side edge of a carrier will bepositioned when a carrier is captured by the gripper. Unless a carrieris present light from the LED will not be reflected onto thephotodetector. However, when a carrier is present, light from the LEDwill be reflected off a side edge of the carrier and impinge upon thephotodetector, causing it to generated an output signal, indicating thepresence of a carrier.

Gripper finger 201 has a base 211, through which bores 213, 215, aredrilled for accommodating centrally located bushings of guide shafts221, 223, while a third bore 217 receives a first end of a pneumaticsupply rod 225. Bores 213, 215 extend completely through base 211, whilebore 217 extends only partially into the base. A rear interior topcorner 228 of base 211 is chamfered to engage a spreading wedge mountedto the bottom of top plate 23 of the housing for the purpose ofimparting a prescribed separation of gripper finger 201 from sensorblock 204 when the carrier gripper is positioned at the magazine stationin preparation for receiving an extracted carrier. Extending from base211 is a bar portion 231 having a ledge 233 and terminating at a forwardwall 235. An overhang plate 237, which partially overhangs ledge 233 ismounted atop bar portion 231. Similarly, gripper finger 202 has a base212, through which bores 214, 216, are drilled for accommodatingcentrally located bushings of guide shafts 222, 224, while a third bore218, aligned with bore 217 in base 211, receives a second end of apneumatic supply rod 225. Bores 214, 216 extend completely through base212, while bore 218 extends only partially into base 212. A rearinterior top corner 229 of base 212 is chamfered to engage the spreadingwedge mounted to the bottom of top plate 23 of the housing for thepurpose of imparting a prescribed separation of gripper finger 202 fromsensor block 204 when the carrier gripper is positioned at the magazinestation in preparation for receiving an extracted carrier.

Extending from base 212 is a bar portion 232 having a ledge 234 andterminating at a forward wall 236. An overhang plate 238, whichpartially overhangs ledge 234 is mounted atop bar portion 232. Theoverhang plates are of sufficient width to allow a carrier to drop ontoand be supported by ledges 233 and 234, for a first degree of separationof the gripper fingers, and then provide a partial overhang of edges ofan extracted carrier when the separation between the gripper fingers hasbeen reduced to prevent canting or tilting of a carrier from itshorizontal orientation, particularly during downward translation of thegripper to bring the carrier into registration with alignment posts onthe anvil. In addition, respective topside edges 239, 240 of theoverhang plates are chamfered to assist in guiding a dropped carrierinto position on the underlying ledges 233, 234.

Bases 211, 212 further include respective partial bores 241, 242, whichreceive bias springs 243, 244 that are seated in associated bores 245,246 in a generally U-shaped gripper support block 63. Bias springs 243,244 serve to bias gripper fingers 201, 202 toward each other to a`closed finger` configuration, shown in FIG. 22. In their closedconfiguration, the gripper fingers are spaced apart slightly wider thanthe width of a carrier so as to provide a very slight amount of play onthe ledges, which serves to facilitate registration of the tape duringits placement upon the anvil, as will be described below.

Sensor block 204 has bores 251, 252 for receiving first ends of guideshafts 221, 223 and first ends of guide shafts 222, 224. Block 204 alsohas a bore 254 through which pneumatic supply rod 225 passes and apneumatic supply port 256 for connecting an air supply to pneumaticsupply rod 225 Opposite ends of rod 225 are recessed to receive O-ringsfor sealing the ends of rod 225. As a consequence, when air is suppliedvia supply port 256 to and exits opposite ends of rod 225, the sealprovided by the O-rings causes pressure to be exerted against theinterior ends of partial bores 217 and 218, thereby imparting aseparation force against the bias of the springs, as diagrammaticallyillustrated within bore 217 of gripper finger 210 shown in FIG. 23. Thispneumatically supplied separation force is employed to fully open thegripper fingers (against the interior sidewalls of gripper support 63)and allow a previously captured carrier to drop free onto the carrierdiscard rails.

U-shaped gripper support block 63 has first and second spaced apart legs261, 262 which extend horizontally from a base portion 260. Interiorsidewalls surfaces 264, 265 of the legs have bores 245, 246 againstwhich closure bias springs 243, 244 are seated, as described above. Leg261 has bores 271, 273 aligned with bores 213, 215 in base 211 forreceiving second ends of guide shafts 221, 223. Similarly, leg 262 hasbores 272, 274 aligned with bores 214, 216 in base 212 for receivingsecond ends of guide shafts 222, 224. Base portion 260 of support block63 has a recess 277 for accommodating a bend in a sensor communicationline, in particular an optical fiber 281, which passes through a bore283 that extends from the rear surface 285 of base 260 to the recess277.

Gripper support block 63 is mounted by way of a set of vertical posts290 for vertical displacement with respect to shuttle base block 67.Specifically, gripper support 63 has a first pair of bores 291, 292which are sized to accommodate vertical guide posts 295, 296 which aresupported by linear ball bushings 298, 299 in bores 301, 302 of shuttlebase block 67. Gripper support 63 further includes a second pair ofbores 305, 306, which are sized to accommodate guide posts 307, 308which are captured in bores 311, 312 of shuttle base block 67. The upperends of guide posts 307, 308 have retaining rings 315, 316 which aresized to engage respective recesses 317, 318 of carrier gripper supportblock and thereby the height of vertical travel of gripper support 63above base block 67. Gripper support 63 also has a third pair of bores321, 322 into which upper ends of a pair of vertical displacementcontrol rods 325, 326 are press fit. The lower ends of rods 325, 326have O-rings 327, 328 to provide a pneumatic seal with the sidewalls ofa pair of bores 331, 332 in shuttle base block 67. Bores 331, 332 areported to pneumatic supply lines 333, 334. The application of acontrolled air supply to lines 333, 334 exerts a lifting force to thebottom surfaces of rods 325, 326, thereby displacing gripper support 63upwardly until retaining rings 315, 316 come in contact with recesses317, 318, thereby limiting the vertical travel of gripper support abovecarrier gripper support block 67. As shown in FIG. 24, this liftingforce overcomes a normal downward bias supplied by extension springs337, 338 top ends of which are mounted to support rungs 341, 342 mountedat the rear surface of gripper support block 63 and lower ends of whichpass through apertures 347, 348 in base block 67 and are secured by bars351, 352 against the bottom surface 354 of the base block. Consequently,gripper support block 63 is normally biased downwardly by springs 337,338, with the spacing between gripper support block 63 and shuttle baseblock 67 being defined by the height of rods 325, 326 the lower ends ofwhich become seated against the bottoms of bores 331, 332 in shuttlebase block 67.

Shuttle base block 67 further includes a generally cylindrical recess361 sized to accommodate a vertically positioned spent carrier discardair cylinder 73. Cylinder 73 has an output shaft 365 to which push plate75 is mounted. As described previously, during the shuttle carrier'sreturn to the magazine station from the die press station, cylinder 73is operated, so that push plate 75 will be raised to engage a spentcarrier (if present) resting on the discard rails Shuttle base block 67may be mounted to an underlying carriage block (not shown) by means of aset of screws passing through a set of four mounting holes 375-378.

The manner in which the carrier gripper components of the carriershuttle operate to capture, transport and release a carrier isdiagrammatically illustrated in FIGS. 25-28. In particular, FIG. 25shows a top view of the carrier gripper at magazine station 14, with airsupplied to bores 331, 332 of base block 67, so that rods 325, 326 liftthe carrier gripper to its carrier-receiving position directly beneaththe magazine. In this position, the chamfered corners 228, 229 ofgripper fingers 201, 202 engage the corners 371, 372 of a spreadingwedge 370, so as to impart a slight separation of gripper fingers 201,202 from the sides of sensor block 204. This separation (e.g. on theorder of 50 mils) is sufficient to allow a carrier 13 to pass betweenthe interior edges of overhang plates and come to rest upon ledges 233and 234 of gripper fingers 201, 202, as shown in FIG. 26.

When an extracted carrier has dropped from the bottom of the magazineonto the shuttle, sensor 208 light from the LED in the sensor 208 isreflected off a side edge of the carrier received by an adjacentphotosensor device of the sensor, which generates an output signalindicating that a carrier has been captured an therefore the shuttle maybe translated to the die press station.

When the shuttle carrier leaves the magazine station, the gripperfingers no longer engage spreading wedge, so that the closing action ofbias springs 243, 244 urges the gripper fingers against the sides of thesensor block 204. In this `closed` position overhang plates 237, 238 nowextend partially above the edges of the carrier, as shown in FIG. 27,delimiting vertical movement of the carrier in its captured condition.

As the shuttle is translated along rail 28 to the die press station, a(magnetic) position sensor (not shown) on the shuttle traverse aircylinder 33 detects when the piston is adjacent to the detector andthereby the shuttle has arrived at the die press station, with thegripper now located directly over the anvil and beneath the die press.The pneumatic supply to bores 331, 332 is then controllably exhausted,so that the gripper support block is gradually lowered by the biasingaction of springs 337, 338. As the carrier is lowered onto the anvil,sprocket holes in the carrier are engaged by corresponding alignmentposts on the anvil.

Because of the overhang plates, the carrier is prevented from beingtilted `off axis` and becoming `hung up` on the anvil. As a consequence,if there is a slight misregistration of the sprocket holes and thevertical alignment pins as the carrier gripper is lowered onto theanvil, the overhang plate imparts a horizontal bias to the carrier. Thishorizontal urging of the carrier brings the tape into registration withthe alignment posts of the anvil, whereby the part is accuratelyregistered on the die anvil.

After the part has been excised from the carrier, with its leads formedby the downward motion of the die press, the die press is liftedvertically out of the way to allow the shuttle to raise the spentcarrier off the anvil. Air is again supplied to bores 331, 332 liftingrods 325, 326 and raising the gripper support. The shuttle is thentranslated back to the magazine station as the die anvil is presentforward to the output station 51.

As the shuttle approaches the magazine station, cylinder 73 is energizedto raise push plate 75 slightly above the height of the discard rails.Should a previously discarded carrier be resting on the rails it will bepushed off by push plate 75 and fall through a discard aperture in therear of the housing base plate and into the discard bin.

When the shuttle arrives at the magazine station, air is suppliedthrough port 256 in sensor block 204, so that gripper fingers 201, 202are urged into their fully open state. As shown in FIG. 28, theseparation between fully open gripper fingers 201, 202 is now sufficientto allow the spent carrier 13 to drop past ledges 233 and 234 onto thediscard carrier rails 77. With the spent carrier now discarded, the airsupply to port 256 is terminated, whereby bias springs 243, 244 urge thegripper fingers together, so that they close upon spreading wedge 370and are thereby properly spaced apart from one another, in the mannershown in FIG. 25 and 26, for receiving and capturing a newly deliveredcarrier.

Referring now to FIGS. 29-32, the configuration of the press station 31comprised of a press-driven lead-clamping, forming and severing unit 39and an associated translatable anvil 41 will be described. As shown inthe top view of FIG. 29 and the partial side view of FIG. 30,translatable anvil 41 comprises a lower platen 401, to the top surfaceof which a generally square shaped anvil block 405 is affixed. Anvilblock 405 has a stepped cylindrical bore 407 sized to accommodate anejector button 411 having a reduced diameter solid central stem portion413 and a surrounding wider diameter body portion 415. Body portion 415has a deep annular groove 417 which receive a compression spring 419.Compression spring 419, when seated within annular groove 417 iscaptured between the bottom of the groove and upper surface 421 ofstepped cylindrical bore 407, so as to urge ejector button 411downwardly, and out of the way of a circuit component 13C of carrier 13.Ejector button 411 also retains an O-ring 423 sized to form a seal withthe interior sidewall 425 of bore 407. The lower portion of bore 407 isported to a pneumatic supply through which air is supplied to the borefor controllably urging ejector button 411 upwardly against the downwardbias of spring 419, whereby stem portion 413 comes into contact with thebottom of the part and lifts the part, so that it may be removed.

Anvil block 405 has a raised clamping surface region 431 upon which theleads 433 of the part rest when the carrier 13 is lowered intoregistration on the anvil. Adjacent to clamping surface region 431 arelead forming surfaces 422, 424. Mounted on lower platen 401 in spacedapart relationship to anvil block 405, so as to leave a gap 437therebetween, is a set of four generally L-shaped outer support blocks435. Each outer support block 435 has a lead support rail 441 and a slot443 through which a vertical alignment post or pin 445 may extend. In anactual embodiment two support blocks 435 on opposite sides of anvilblock 405 are provided with vertical alignment pins 435.

Also affixed to lower platen 401 are a pair of journalled verticalbushings 434 into which a pair of associated precision fit guide postson an upper platen pass, when the die press lowers the upper platen ontothe die anvil in the course of clamping, excising and forming the leadsof a part.

As noted above, as the carrier is lowered onto the anvil, a respectivesprocket hole 446 in the carrier is engaged by alignment post 445 and,because of the provision of overhang plates on the carrier gripperfingers, the carrier is prevented from being tilted or canted andbecoming `hung up` on the anvil. The slight amount of horizontal play onthe support ledges of the gripper fingers enables the overhang plates tourge the carrier sideways to the extent necessary to bring the carrierinto alignment with posts 445, so that the carrier is accuratelyregistered on the anvil.

Lead clamping, excising and forming unit 39 is shown in the diagrammaticplan view of FIG. 31 and the partial side view of FIG. 32 as comprisingan upper platen 451 upon the lower surface 453 of which a floatingclamping block 455 is mounted. Floating clamping block 455 is supportedagainst compression springs 452 which are captured in recesses inclamping block 455 and upper platen 451. Clamping block guide pins 454extend into recesses 456 in lead forming and severing blocks 461, whichare rigidly attached to upper platen 451 adjacent to clamping block 455.The lower ends 462 of lead forming and severing blocks 461 are contouredto shape the excised leads of the part as they bend the leads downwardlyand cause the bent lead to bottom out against the lead forming surfaces422 and 424 of anvil block 405.

Upper platen 451 and the lead forming components it supports are mountedsolid with the output shaft of the press, so that there is no mutualtranslational movement among the forming and excising parts, therebyassuring precision forming and severing of the extremely fine toleranceleads, something which would not be possible using a conventionalfloating anvil system, where play among the forming parts is afforded.Because of the integral (solid) mounting of the forming parts with theupper platen, precision control of the forming force is necessary. Forthis purpose the downward pressure applied by the press is controlled byan adjustable pressure regulator, so that a precise forming force willbe imparted to the free ends of the clamped leads.

Clamping block 455 contains a set of four raised annular clamping edges457 each of which is sized to form alignment with clamping surfaceregions 431 of anvil block 405 when anvil 41 is brought into verticalregistration with press 35 at press station 31. Mounted on upper platen451 adjacent to clamping block 455 is a set of four lead forming andsevering blocks 461, positioned to engage the free ends of leads 433,and bend those free ends against forming surfaces 422, 424 of anvilblock 405. An outer corner 463 of each block 461 has a sharp severingedge for cutting the formed leads. Also mounted on upper platen 451adjacent to clamping block 455 is a set of tie strip severing blocks471, positioned to engage diagonally extending support tie stripslocated at the corners of the carrier and its supported component. Aninner corner 473 of each tie strip severing block 471 has a sharpsevering edge for cutting the diagonal tie strips.

To provide precision alignment of the upper platen-mounted components ofthe lead clamping, excising and forming unit 39 with the die anvil 41,upper platen 451 has a pair of guide posts 472 at the lower ends ofwhich respective ball bushings 474 are provided. Guide posts 472 arepositioned on upper platen 451, so as to be in precision alignment withjournalled vertical bushings 434 on lower platen 401. As the die presscontrollably lowers upper platen 451 toward lower platen 401, ballbushings 474 enter journalled bushings 434, with zero clearance (withoutplay), so that there is no horizontal translation of the die anvilrelative to the upper die excising and forming components.

Referring to FIG. 33, a diagrammatic side view of a transport cart forsupporting and transporting the above described tape automated bondingfeeder apparatus is shown as comprising a base frame 501 supported forrolling movement upon a floor surface 503 by way of a set of castors505. A generally H-shaped support frame 507 having vertical post members511, 512 and a horizontal beam 512 is affixed to the base frame 501. Avertical support frame 515 having a threaded height adjustment footscrew 517 at its lower end 519 is mounted to post member 511 of frame507 by way of a vertical guide shaft member 521 which passes throughsupport blocks 523, 525 on frame 515 and associated support blocks 533,535 on post member 511. Vertical guide shaft member 521 permits theheight of frame 515 to be vertically adjusted with respect to base 501.A carrier receptacle 538 is supported by support frame 507 beneath thelocation of the feeder where spent carriers are discarded.

A feeder mounting plate unit 541 which provides a support base for thefeeder is affixed to an upper end 520 of frame 515. The mounting plateunit includes a lower plate 543 and a leveling plate 545 mounted atoplower plate 543 by a set of leveling screws (not shown). The feederitself is mounted on leveling plate 545. One or more alignment elements551, in the form of side extending threaded guide rods, are affixed tothe mounting plate unit, and are arranged to engage associated alignmentelements 553 mounted to a circuitboard-assembly workbase 555 whereatparts removed from the feeder are processed.

With the height of the feeder mounting plate adjusted for a particularworkbase, an operator brings the feeder transport unit up to the side ofthe workbase so that the guide rods engage associated alignment elements(e.g. recesses in alignment plates on the side of the workbase). Becausethe guide rods are threaded, the distance by which they extend from theside of the transport unit may be adjusted to obtain precision spacingbetween the location of the feeder and the workbase. It should be notedthat the width of the transport unit (in the direction into the drawing)is typically large enough to accommodate a plurality of feeders that aremounted to the top plate of the transport unit in a side by sidearrangement to enable the pick and place unit of the assembly apparatusready access to a plurality of different circuit part types.

This multiple type part feed and form capability may be significantlyenhanced in accordance with a second embodiment of the feeder, which hasa multiple magazine configuration, a top view of which isdiagrammatically shown in FIG. 34. In particular FIG. 34 shows anarrangement of plural (different length) feeders (four in theillustrated example) 601, 602, 603, 604 are arranged in a side by sidelayout on the top of the transport unit. The locations of the magazinesof adjacent feeders are offset from one another so as to permit eachfeeder to accommodate multiple magazines that are translatableorthogonal to the lengthwise dimension of the feeders and thereby allowa selected magazine to be controllably positioned over the carrierdelivery opening in the top plate of the housing of a respective feeder.

In the illustrated example, each feeder accommodates three magazines11-1, 11-2, 11-3 which are mounted on horizontally translatable plates610 alternately offset for adjacent feeders thereby permitting plates610 to be moved back and forth without mutual interference. The magazinesupport plates may be translated by a rack and pinion mechanism (notshown) or other conventional translation device, the control for whichis supervised by microcontroller 100. It will be noted that in thepresent example feeders 601, 603 have extended bases 611, 613 to providefor alignment of each of the presentation stations alongside theworkbase of the assembly unit.

As will be appreciated from the foregoing description, the presentinvention obviates the problems of conventional TAB feeder systems by areduced hardware volume apparatus which successively feeds individualones of a plurality of carrier-retained electronic circuit components toa pick and place device for placement and attachment to a circuit boardwithout having to sideways translate the carriers of the stack, therebypreventing surface anomalies on the surfaces of adjacent carriers in thestack from impeding the feed process. Because the carriers can beextracted vertically from the magazine onto a carrier shuttle, andthereby readily delivered to a lead forming unit, the presentation of anexcised and processed part to a board-assembly pick and place device isfacilitated.

While I have shown and described several embodiments in accordance withthe present invention, it is to be understood that the same is notlimited thereto but is susceptible to numerous changes and modificationsas known to a person skilled in the art, and I therefore do not wish tobe limited to the details shown and described herein but intend to coverall such changes and modifications as are obvious to one of ordinaryskill in the art.

What is claimed:
 1. An apparatus for successively supplying respectiveones of a plurality of electronic circuit components to an outputstation from which a component is seized for placement and attachment toa circuit board comprising, in combination:a housing; a magazine, inwhich a plurality of circuit component carriers are arranged in astacked configuration, mounted on said housing, said magazine having acarrier extraction unit at one end thereof which controllably allows anindividual component carrier at one end of said stack to drop away fromsaid stack; a carrier shuttle, supported for movement between a firstlocation of said housing beneath said one end of said magazine and asecond location of said housing, said carrier shuttle receiving andsupporting a carrier dropped from said magazine for placement on a leadforming unit at said second location of said housing; a lead formingunit at said second location of said housing, said lead forming unitbeing arranged to separate a component from a component carrierdelivered thereto by said shuttle and to form the leads of a separatedcomponent into a prescribed shape for mounting the separated componentto a circuit board; and a component transport unit coupled to said leadforming unit and arranged to transport a separated component, the leadsof which have been formed by said lead forming unit, to said outputstation.
 2. An apparatus according to claim 1, wherein said lead formingunit comprises an upper lead-clamping, bending and cutting unit mountedat said second location of said housing, and a lead-forming anvilmounted to said component transport unit.
 3. An apparatus according toclaim 2, wherein said lead forming unit comprises an upper floatinglead-clamp, and bending and cutting members rigidly mounted to avertically displaceable member at said second location of said housing.4. An apparatus according to claim 3, wherein said lead forming unitcomprises a controllable press for controllably displacing saidvertically displaceable member, to which said bending and cuttingmembers are rigidly mounted, and thereby controlling the lead bendingand cutting pressure imparted by said lead forming unit upon said advil.5. An apparatus according to claim 2, wherein said component transportunit is arranged to transport said anvil between said second location ofsaid housing and said output station.
 6. An apparatus according to claim5, wherein said carrier shuttle is configured to retain, in a generallyloose fit, horizontal condition, a component carrier that has beendropped from said one end of said magazine.
 7. An apparatus according toclaim 6, wherein said carrier shuttle comprises support frame upon whichfirst and second spaced apart retention members are mounted, saidretention members being translatable with respect to each other andbeing arranged to support and retain edge portions of a carrier, whileallowing a limited degree of horizontal play of a carrier retainedthereby.
 8. An apparatus according to claim 1, wherein said upperlead-clamping, bending and cutting unit has a zero-clearance alignmentmember arranged to engage a corresponding alignment element fixedlymounted with respect to said lead-forming anvil.
 9. An apparatusaccording to claim 1, wherein said anvil includes an ejector elementcontrollably urged into contact with a formed part that has been excisedfrom a carrier, so as to lift the part off the anvil and facilitate itscapture by a part seizure device at said output station.
 10. Anapparatus according to claim 1, wherein said lead forming unit beingarranged to form the leads of a separated component into a gull-wingshape for surface-mounting the separated component to a circuit board.11. An apparatus according to claim 1, wherein said carrier extractionunit includes a first controllable shutter unit which controllably opensto allow the lowermost component carrier within said magazine to droptherethrough to said shuttle and an adjacent carrier engaging unit whichretains a next lowermost component carrier in place as said lowermostcomponent carrier is allowed to drop away from said one end of saidmagazine and thereafter allows said next lowermost carrier to move intoposition as the lowermost component carrier within said magazine.
 12. Anapparatus according to claim 1, wherein said carrier shuttle is arrangedto transport to, and release at a third location of said housing, acarrier from which a component has been separated.
 13. An apparatusaccording to claim 12, wherein said output station is configured toallow vertical access to a part that has been transported to said outputstation by said component transport unit.
 14. An apparatus according toclaim 1, wherein said lead forming unit comprises a lead forming anviltranslatable between said second location and said output station and adie press unit having a lead forming die controllably engageable withsaid lead forming anvil, so as to remove a component from a carrier thathas been placed into registration on said anvil by said shuttle and formthe leads of the removed component, and wherein the force exerted bysaid die upon leads of a part borne by a carrier registered on saidanvil is externally controllable.
 15. An apparatus according to claim14, wherein said anvil includes at least one alignment pin oriented toengage carrier registration element of a carrier delivered by saidshuttle to said second location whereat said die press is provided. 16.An apparatus according to claim 14, wherein said anvil further includesan ejector element controllably urged into contact with a formed partthat has been excised from a carrier, so as to lift the part off theanvil and facilitate its capture by a part seizure device at said outputstation.
 17. A method for successively supplying respective ones of aplurality of electronic circuit components to an output station fromwhich a component is seized for placement and attachment to a circuitboard comprising the steps of:(a) stacking a plurality ofcomponent-containing carriers in a generally vertically oriented storagemagazine; (b) controllably causing an individual component carrier atthe bottom of said stack to drop away from said stack onto a carriershuttle, which is supported for movement between said magazine and alead forming unit spaced apart from said magazine; (c) translating saidcarrier shuttle to said lead forming unit and bringing the componentborne by said carrier into engagement with said lead forming unit; (d)causing said lead forming unit to separate a component from a componentcarrier delivered thereto by said shuttle and to form the leads of aseparated component into a prescribed shape for mounting the separatedcomponent to a circuit board; and (e) translating a separated component,the leads of which have been formed by said lead forming unit, to saidoutput station.
 18. A method according to claim 17, wherein said leadforming unit comprises an upper lead-clamping, bending and cutting unitmounted at said second location of said housing, and a lead-forminganvil mounted to said component transport unit, and wherein saidcomponent transport unit is arranged to transport said anvil to saidoutput station.
 19. A method according to claim 17, wherein step (b)comprises retaining an individual component carrier that has droppedaway from said stack onto said carrier shuttle in a generally horizontalcondition.
 20. A method to claim 17, wherein step (b) comprisesproviding a carrier extraction unit at the bottom of said magazine, saidcarrier extraction unit including a first controllable shutter unitwhich controllably opens to allow the lowermost component carrier withinsaid magazine to drop therethrough to said shuttle and an adjacentcarrier engaging unit which retains a next lowermost component carrierin place as said lowermost component carrier is allowed to drop awayfrom said one end of said magazine and thereafter allows said nextlowermost carrier to move into position as the lowermost componentcarrier within said magazine.
 21. An apparatus for successivelysupplying respective ones of a plurality of electronic circuitcomponents to an output station from which a component is seized forplacement and attachment to a circuit board comprising, in combination:ahousing having an aperture through which a component carrier may pass; aplurality of magazines, in each of which a plurality of circuitcomponent carriers are arranged in a stacked configuration, translatablymounted with respect to the aperture of said housing, each magazinehaving a carrier extraction unit at one end thereof which controllablyallows an individual component carrier at one end of said stack to dropaway from said stack through said aperture, when said each magazine isaligned over said aperture; a carrier shuttle, supported for movementbetween a first location of said housing beneath said aperture and asecond location of said housing, said carrier shuttle receiving andsupporting a carrier dropped from said a magazine for placement on alead forming unit at said second location of said housing; a leadforming unit at said second location of said housing, said lead formingunit being arranged to separate a component from a component carrierdelivered thereto by said shuttle and to form the leads of a separatedcomponent into a prescribed shape for mounting the separated componentto a circuit board; and a component transport unit coupled to said leadforming unit and arranged to transport a separated component, the leadsof which have been formed by said lead forming unit, to said outputstation.
 22. An apparatus according to claim 21, wherein said leadforming unit comprises an upper lead-clamping, bending and cutting unitmounted at said second location of said housing, and a lead-forminganvil mounted to said component transport unit.
 23. An apparatusaccording to claim 22, wherein said component transport unit is arrangedto transport said anvil between said second location of said housing andsaid output station.
 24. An apparatus according to claim 23, whereinsaid carrier shuttle is configured to retain, in a generally horizontalcondition, a component carrier that has been dropped through saidaperture.
 25. An apparatus according to claim 21, wherein said carrierextraction unit includes a first controllable shutter unit whichcontrollably opens to allow the lowermost component carrier within amagazine to drop therethrough to said shuttle and an adjacent carrierengaging unit which retains a next lowermost component carrier in placeas said lowermost component carrier is allowed to drop away from saidmagazine through said aperture and thereafter allows said next lowermostcarrier to move into position as the lowermost component carrier withinsaid magazine.
 26. An apparatus according to claim 25, wherein saidcarrier shuttle comprises support frame upon which first and secondspaced apart retention members are mounted, said retention members beingtranslatable with respect to each other and being arranged to supportand retain edge portions of a carrier.